Geological Survey-Work in Minnesota.—The law of 1872, under which the Geological Survey of Minnesota was instituted, was intended, according to Prof. N. H. Winchell, to place the survey in close connection with the State University; and the professorship of Geology and Mineralogy in the university was maintained for six years at the expense of the survey fund. From it the museum of the university has obtained the nucleuses of growing geological, zoölogical, and archæological collections. The survey was supported by legislative appropriations till the revenue from the sale of salt-springs lands supplied their place. The economic side of the enterprise has been kept in mind constantly, though it has not been conspicuous. "The annual reports embody common facts, and description cast in a semi-scientific mold. They are addressed primarily to a home constituency, in order to show them the utility of the work of the survey. As the survey becomes grounded in the good-will of our own citizen?, it is strengthened for doing more advanced work, and at the same time finds a constituency that is ready to welcome more strictly scientific publications." Among the most important results of the work of the survey have been the saving of the salt-springs lands from being devoured by speculative enterprises; dissuading citizens, by the publication of correct information on the subject, from making fruitless searches for coal; calling attention to the economic resources of the State; and showing the people how to secure cheaply a supply of pure water for domestic purposes. The scientific results, while not including any great new discoveries, have been numerous, and all have a place in the elucidation of geological theory. The unfinished work of the survey lies in the northern part of the State, and, embracing the crystalline rocks and the various questions of economic and technical geology that pertain to them, is the most important as well as the most difficult and costly part of its work.

Summer Courses at Harvard.—The courses of summer instruction at Harvard University will include four courses in chemistry (general elementary chemistry, qualitative analysis, quantitative analysis, and organic chemistry); courses in experimental physics and botany, geology (elementary and advanced); topography, French, German, and physical training; and courses at the medical school. A general course of lectures on methods of instruction will be given in addition by teachers in the several departments represented by the schools, open free to all members of the summer schools. Persons are admitted as special students in the university who desire to pursue for a year or more the study of some particular subject; and who, having received a high-school or academy training, wish to follow for one or more years a course of liberal study preparatory to some profession or to the walks of active life. The summer courses will open on different days between June 30th and July 9th, inclusive.

Nature's Earth-Carving.—As the tools used by Nature in carving the earth, Dr. Archibald Geikie enumerates air, rain, rivers, springs, and frost. , Exposure to the air changes the hardest rocks. Cracks form in them which receive the rain and are enlarged by freezing in winter, to increase the effect of the next season's rain in washing away the surface. No rock wears away faster than white marble, the destruction of which is speeded by the carbonic acid in the air. The waste in a century sometimes amounts to a third of an inch in thickness. The more compact kinds of sandstone endure better, and in tombstones still, after the lapse of two centuries, show marks of the chisel. Sandstones, however, usually contain a layer more soluble than the rest, along which the rock splits and peels. Compact rocks like granite are traversed by parallel joints on which the weather acts destructively; and the less compact clays, dried to powder, are blown by the wind and swept more rapidly into rivers, lakes, and the sea. The rain-streams, always running over the same channels, furrow the hill-side and wear it away still more rapidly; and a sheep-walk in a few years may become a deep ravine. The material carried down, when spread at lower levels, helps to form plains like meadows, and these in time may be cut through and partially carried away. Streams descending from peaty regions are charged with carbonic acid, and destructive to limestone. In all mountain regions the rivers are liable to enormous increase in volume from heavy rainfalls, when they carry off proportionately larger quantities of earth. The work of springs is like that of rain and rivers. The sink-holes in limestone regions carry the water down underground to do a similar work there; and this underground flow of water often helps in the production of landslips, especially when the ground is covered with bowlder-clay.

Teaching the "New Botany."—In the "New Botany," as described by Prof. W. J. Beal, in Garden and Forest, pupils are set to studying plants before books. Previous to the first lesson, "each pupil is furnished or told where to procure some specimen for study. If it is winter, and flowers or growing plants can not be had, give each a branch of a tree or shrub, which may be two feet long. The examination of these is made during the usual time for preparing lessons, and not while the class is before the teacher. For the first recitation each is to tell what he has discovered. The specimens are not in sight during the recitation. In learning the lesson, books are not used; for, if they are used, no books will contain a quarter of what the pupil can see for himself. If there is time, each member of the class is allowed a chance to mention anything not named by any of the rest. The pupils are not told what they can see for themselves. An effort is made to keep them working after something which they have not yet discovered. If two members disagree on any point, on the next day, after further study, they are requested to bring in all the proofs they can, to sustain their different conclusions. Give other specimens for the next lesson, keep reviewing, and generalize as details and facts accumulate. I like to give two species for careful comparison. . . . After a few weeks, reviews may be made in connection with chapters in some book. I make it a rule to give pupils specimens for study and comparison regarding every chapter in Gray's Structural Botany before the book-lesson is studied. I place no stress on making these investigations in the order in which the chapters of a text-book are arranged. Free use is made of our botanic garden, the crops in the vegetable-garden, fields, and experiment station, and the thickets along the river. Special topics are often assigned, in which each student has to go many times to observe and record observations on his growing plant." Illustrations by drawing are a prominent feature of the whole course.

Leaning Towers.—The leaning tower of Pisa is not the only building of its kind. There are many towers in northern Italy that deviate from the perpendicular, so that a writer has spoken of the country as "a land of towers staggering in all directions like tipsy men"; and there are in England few spires of any great altitude that are quite upright. The inclination of the Italian towers is a result of the character of the foundation soil, and of mistakes in building. The soil and subsoil of northern Italy down to the water-level are composed of rounded stones brought down by torrents and rivers from the Alps. A broad foundation is a primary condition of the stability of buildings erected upon it. The builders of the towers had classic models in their eyes, and did not contemplate the broadening of bases or the adding of buttresses to insure stability. Consulting appearances, and not venturing to depart from the conventional, they built straight up. The pressure concentrated on the narrow base was too much for the shifting stones beneath. They yielded at the weaker points, and the towers bent over. If the builders had minded the example of their Gothic neighbors and widened their bases, the load would have been more evenly distributed over more ground, and the deviation from the perpendicular would not have been so obvious. There are many leaning towers in Bologna, inclining in all directions; and few of the campaniles of Venice are perfectly upright.

Palæolithic Implements in the United States.—The Palæolithic implements of the District of Columbia, and indeed from all over the United States, as described by Mr. Thomas Wilson, are always chipped, never polished; are almond-shaped, oval, or sometimes approaching a circle; have their cutting edge at or toward the smaller end, and not, as in the Neolithic specimens, toward the broad end; are frequently made of pebbles, and with the original surface sometimes left unworked in places; and are exceedingly thick compared with their width, so much so as to make it apparent that they were never intended to have a shaft or handle after the fashion of the axe or arrow or spear-head. They were usually made of quartz, quartzite, or argillite; while the Neolithic man used any material that would grind to a smooth surface. They are not known to have been used by the American Indian, who when found by Europeans was in the Neolithic stage. Of the thousands of Indian mounds, cemeteries, graves, and monuments which have been explored, not one has ever yielded these Palaeolithic implements. The articles found in the District of Columbia are of the same type as Palæolithic implements found in the Trenton gravels; at Little Falls, Minn.; in Jackson County, Ind.; at Claymount, Del.; and at Loveland, Ohio; and all together contribute to prove that a real Palaeolithic period existed in the United States.

Sharing of Earnings.—After several years of experimenting, Mr. Alfred Dolge, of Dolgeville, Herkimer County, New York, has decided upon a plan for sharing with his employés the earnings of his manufacturing business. A share of the net earnings of the business is to be set aside each year, and applied for the benefit of the employés in three ways—as pensions, insurance, and endowment. Every male employé who becomes unable to work after a continuous service of ten years receives a pension equal to fifty per cent of his wages. Each three years of service over ten up to twenty-five, increases the pension ten per cent. A disabling accident happening to an employé while on duty entitles him to a fifty-per-cent pension, even if he has not served ten years. Employés are also entitled to a life-insurance policy for one thousand dollars after five years' service, to a second one after ten years, and a third after fifteen years. For each employé rejected by the insurance company with which the house contracts, and for those entering the service of the house when over forty years old, thirty-five dollars a year is deposited instead of the policy. After five years of consecutive service, also, an account is opened with each employé, upon which he will be credited at the end of each year according as the manufacturing record shows that he has earned more than has been paid him in the form of wages. If through gross carelessness any employé has caused the house a loss, such loss will be charged against this account. This endowment money shall be payable when the employe reaches the age of sixty years, or upon his death. Against this account the employe may obtain a loan by paying interest and furnishing collateral security. Mr. Dolge is convinced that this scheme is superior to what is known as profit-sharing, because it is not projected from any idea of benevolence, but is based on self-interest. It places the employé on the same level with his employer; it puts him on his mettle, and rewards him according to his own merit. The main objection which Mr. Dolge has to the ordinary profit-sharing plan is that it gives the lazy and incompetent workman the same percentage in addition to his wages as it gives to the intelligent and industrious employé, who has perhaps earned for his employer twice as much as the former.

Science and Poetry.—Writing upon Browning's Science in Poet Lore, Dr. Edward Berdoe maintains that, "other things being equal, the poet who knows his natural history, his botany, and his physical science, will write better poetry than he who knows nothing of these things." The author has for some years been pointing out how Browning's scientific imagination and learning enhance the value of his poetic work and his claims to recognition as a great teacher of the nineteenth century. His work is "as distinctively the product of the age of science as Petrarch's of the revival of learning." There is not a mood of the human mind, Dr. Berdoe continues, which is beyond the power of this poet to analyze and explain. "Analysis with him becomes invective. He is 'the maker,' because he is so great an analyst. Analysis with genius such as his leads to synthesis, and for this he is called a scientific poet." His poems teem with instances of the influence which modern scientific discoveries have exercised upon his genius, and this possibly is one element in their obscurity. As Max Müller has said that neither Tennyson nor Browning could be understood without an acquaintance with the Greek and Roman classics, so "in Browning's case a knowledge of the physical sciences is also demanded of us; but this only shows that Browning is in advance of his time, as a leader of men should be. The age can not be very distant when an acquaintance with science will be as common as a knowledge of the ancient classics. Then we shall hear less of Browning's obscurity. Browning's theory of life is eminently in accord with the teachings of.evolution and development." It is scientific because he goes into its purpose, and what to the pessimist is infinite mystery is replete with law and order to him. A large number of citations from Browning's poems are given to confirm and illustrate these positions.

Recognition of Pictures by Animals.—A correspondent of The Spectator owns a fox-terrier that had been cured of a tendency to run sheep by judicious punishment. Some time afterward the dog, which had been left in a room for a few minutes with an unfinished painting of sheep and sheep-dogs in the snow, was found gazing intently at the picture and showing all the signs of canine excitement. As the figures of the sheep were only eight or ten inches in length, the owner believed that the dog must have understood that they were supposed to be at a distance from him. The dogs in the picture he apparently entirely ignored. Another correspondent of the same journal tells of a dog who, when shown a life-sized figure of a cat worked in wools on a screen, made a rush for it, and but for his master's clutching him firmly by the collar the screen would have been torn to shreds. A cat is also mentioned who sprang at a bird which her mistress had painted on a fire-screen, and a dog, who disliked being washed, that when shown a large picture of a child scrubbing a fox-terrier in a tub turned away his head ruefully and would not look at his "brother in adversity." These instances are put forward as evidence of animal intelligence. But do they not rather serve as measures of the inferiority of brute to human intelligence? For the dog or cat in each case was deceived by an artificial representation on the flat which would not deceive a human being.

Antiquity of Submarine Warfare.—The efficiency of submarine mines or batteries and of guard-boats and shore defenses is augmented to a wonderful degree when the two systems are made to supplement one another. The combination of them affords the only means now known for compelling the enemy to long and cautious operations when he would like to carry his purpose at a blow. It is possible to evade or defy either system alone, but "even the most dashing commander would hesitate to run past forts and batteries when every channel is alive with destructive charges." The efficiency of mines depends on every part of their arrangement being complete; and while the laying of them is simple enough, they are in practice subject to difficulties and complications from weather, wind, tides, currents, fogs, and shifting ground, that can not be foreseen. These cunning inventions of explosive engines, rams, and torpedoes, though they seem so new and scientific, had their counterparts in the devices of the past. The spar torpedo-boats were like the Greek fire-boats which were described in the thirteenth century as old. The mobile torpedo-boat had its prototype in those drifting or secretly propelled infernal machines that figured in the water-fights of two or three hundred years ago. Fixed submarine mines were described by Gianbaptista Porta in 1608. The principles of these systems are old; all that is new in them is contained in the "modern improvements" and more perfect adaptations. The systematic application of submarine warfare, however, dates from the second half of this century. Louis XIV would have nothing to do with it. Napoleon discouraged Fulton's efforts, because they favored the art of defense as against his offensive operations; and in England Pitt was blamed for experimenting with Fulton's devices because it was encouraging a mode of warfare which, if successful, would be destructive to English supremacy of the seas.

Astronomy on Lake Tanganyika.—According to Père Vyncke, a French missionary, the negroes on the western side of Lake Tanganyika, although the sun passes over their heads twice a year, take no notice of his course, and have no idea of the solar year; but the moon plays an important part in their life. They celebrate its renewing by beating drums, firing shots, and shouting. The new moon is hailed with general dances by most of the African tribes. To keep the run of its age they have a bundle of twenty-eight or thirty sticks, of which they take out one each day. They consult the stars to determine the times for agricultural work, fishing, etc. The rising of the Pleiades marks the sowing season, and is celebrated by dances and festivals in honor of the dead; and the constellation is called kili, or seeds. The milky way is called the line of drought and rain, because the rainy season begins when it rises at sunset. The rising of Orion's belt gives the time for catching a certain fish. Another star, which Père Vyncke does not identify, is called by a name signifying pounding manioc, because that operation is begun when it is at the zenith. Aldebaran is called the Northern and Sirius the Southern Gem. The Centaur, the Southern Cross, and the Ship, including the beautiful star Canopus, which is not visible in the north, are called by names signifying "paths" and "tens," because they point the way to the south pole and are composed of a large number of stars.

Voracity of a Pike.—The following story is told by a correspondent of Land and Water: "I and some friends were fishing in a small river in Hertfordshire, and, sport being poor, were watching a family of moorhens, just hatched. One of the fledglings, venturing too far out, was carried down a swift run, but managed to paddle into an eddy. No sooner, however, was the little creature in this supposed haven of refuge, than there was a swirling movement from below, a quick snap, and the fledgling disappeared in the jaws of a pike. Later on a second chick got carried away and was also swallowed by the pike, and very soon afterward, in spite of one rescue on our parts, a third was sacrificed. This was more than we could stand, and a spinning minnow, very poorly adapted for pike-fishing, was produced. At the second cast the lure was taken, and, fate being propitious, the gut escaped the pike's sharp teeth. Result, a fish of four pounds only. When landed, the last-taken chick fell out of the pike's mouth with an expiring gasp still in it, and, on the fish being held head downward and shaken, the other two made their appearance."

The Ordeal by chewing Rice.—The East Indian method of discovering a thief by the ordeal of chewing dry pounded rice has almost disappeared of late. A case of its successful application many years ago, to discover who had stolen a gold watch that was missing, is described in Chambers's Journal. A native official, who was employed by the government for detecting thieves by the rice ordeal, was called in to conduct the process. The loser of the watch was one of four young Englishmen who occupied a house together. All the servants of the establishment, some forty-odd in number, were seated in two rows on the ground in one of the long verandas of the house. A small piece of green plantain-leaf was first placed in each man's hands. The thief-detector then went round with a bowl of pounded rice, like flour, and with a wooden spoon poured a quantity into the open mouth of each servant. The order was given that each man was, within five minutes, to chew the rice-flour to a pasty mass, and eject it on to his plantain-leaf. Most of the men set to work with a will, though a few were rather frightened at first; but long before the five minutes had elapsed almost every one had got through with the operation, and held the evidence of his innocence in his hands. But why are so many eyes turned toward one man, who sits back as if anxious to avoid observation? We also look, and there is the favorite servant of the loser of the watch, with his face almost convulsed, and trying in vain to get the rice-flour out of his mouth. His lips are dry, and his glands refuse to produce the saliva which is needed to moisten the rice-flour. At last the detector's eyes glare upon him, and pointing at him with his long, bony finger, he says solemnly, "There is the thief!" The victim quails and grovels on the floor before him; he faintly appeals to his master for forgiveness, and promises that he will restore the watch. The convicted thief slowly rises, and requesting his master to follow him, goes to the well in the garden, and produces the gold watch from under a loose brick. This operation savors of magic, but it has a psycho-physiological explanation. It is one of the instances of the influence of mind over body: the anxiety of the culprit evidently arresting the flow from the salivary glands.

Position of the Expert Witness.—The expert, the Chemical News has said, occupies an anomalous position in court. Technically, he is a mere witness; practically, he is something between a witness and an advocate, sharing the responsibilities of both, but without the privileges of the latter. He has to instruct counsel before the trial and to prompt him during its course. But in cross-examination he is the more open to insult, because the court does not see clearly how he arrives at his conclusions, and suspects whatever it does not understand. Hence, not a few of the most eminent men in every department of science distinctly and peremptorily refuse to be mixed up in any affair which may expose them to cross-examination. "I will investigate the matter, if you wish it, and will give you a report for your guidance, but only on the distinct understanding that I am not to enter the witness-box." Such in substance is the decision of not a few men of the highest reputation and the most sterling integrity. Certainly it is not for the interests of justice to render it impossible for such men to give the court the benefit of their knowledge. Further, the spectacle of two men of standing contradicting or seeming to contradict each other, in the interest of their respective clients, is a grave scandal. Thus, our present mode of dealing with scientific evidence is found on all hands unsatisfactory. The outside public is scandalized; experts are indignant; and the bench and the bar share this feeling, but are disposed to blame the individual rather than condemn the system. It was proposed, as a remedy for this evil, that "the expert should be the adviser of the court, no longer acting in the interest of either party. Above all things, he must be exempt from cross-examination. His evidence, or rather his conclusions, should be given in writing, and accepted just as are the decisions of the bench on points of law."

Half a Century of Inventions.—"Those of us not yet fifty years of age have probably lived in the most important and intellectually progressive period of human history," says Iron, and names the following as a few of the inventions and discoveries which have originated or been made practical within the past half-century: Ocean steamships, railways, street-car lines, the telegraph, ocean cable, telephone, phonograph; photography, and a score of new methods of picture-making; aniline colors, kerosene, electric lights, steam fire-engines, chemical fire-extinguishers; anæsthetics and painless surgery; gun-cotton, nitroglycerin, dynamite, and a host of other explosives; aluminum, magnesium, and other new metals; electro-plating, spectrum analysis, and the spectroscope; audiphone, pneumatic tubes, electric motors, electric railways, electric bells, type-writers, steam heating, steam and hydraulic elevators, vestibule cars, cantilever bridges. To these may be added the vulcanizing of rubber, the Bessemer steel process, bicycles, the "Monitor" type of war-vessels, the dynamite gun, and doubtless the list does not now include all of the most important even.

Science in the Laundry.—While washing is declared to be as much a chemical process as dyeing or pattern-printing, there has been very little application of scientific principles to it. The finishing up is held in the laundries to be more important, but is really less so than the preliminary processes of actual cleansing. These are four in number—digesting or soaking, washing, rinsing, and drying. In cleansing, two sources of contamination are to be kept in view—the dirt that comes from without and settles on the clothes, and the soiling that is caused by transpiration from the body. It is most important that the elements of bodily soil be removed, and this is probably accomplished quite as much in the drying as in the washing. We judge of the purity of clothes by their "sweetness." This is, to a large extent, proportioned to the completeness with which they have been acted upon by the atmosphere, or by its great oxidizing agent ozone, and is consequently dependent on the atmospheric conditions under which they are dried. The lesson is, that atmospheric drying is the best, and that laundry drying by artificial heat can not be depended upon to do its work, unless pains are taken to give a free circulation of ozonized air.

Voice-Figures on Glass.—A curious mode of decorating glass is practiced by an English lady, Mrs. Watts Hughes. The figures which she produces are shell-like forms, trumpet and snake like shapes, twisted together and combined, and crossed in various directions by lines, but not exactly like anything in nature. The instrument by which these lines are drawn is the voice, and the method of procedure differs for different figures. For a daisy-like figure, Mrs. Hughes prepares a paste of flake-white powder-color and water. On a thin membrane of India-rubber stretched over one end of a ring, resembling a napkin-ring, she spreads a little water, to which some of the flake-white paste is added, and thus floated all over the disk. This ring is inserted into the lower end of a tube turned up like the letter J. She then sings into the upper end of the tube a low note, firm but not very loud. Tiny globules of the paste are thrown up into the air by the vibration of the membrane induced by the sound, and fall back upon the center of the disk, making a little round heap, like the center of a daisy. Mrs. Hughes then sings a note of a different character from the first, when from the round center of white paste will fly out, at unequal distances, little tentative star-like jets. Sometimes two or three abortive attempts will have been made, when suddenly a symmetrical row of petals will start out and create with the center a dainty daisy-like figure. The pansy form is produced somewhat in the same way as the daisy, but more water is put on the disk in proportion to the paste, and the note is sung differently. In singing the shell and trumpet figures, the paste is made with Prussian blue, madder lake, or other pigment whose weight and character suit it to the vibrations of the particular note to be sung. Glass is rubbed over with the paste when the figures are to be called out upon it as well as the membrane. With a small piece of glass, Mrs. Hughes uses a bent-up tube and moves the glass rapidly round on the disk. Should the glass be too large to hold in the hand, she uses a straight tube, and sings the note while moving it round or along the glass. Specimens of this work were shown in the "Arts and Crafts Exhibition," at London, last fall, and panes decorated in this way form the lower part of the windows in Mrs. Hughes's Home for Little Boys, at Islington. The explanation of the phenomenon is that the particles of coloring-matter are thrown off from the vibrating parts of the membrane and collect on the nodal lines—the lines of no vibration. The nodal lines of vibrating membranes were first thoroughly studied by Savart.

Taming the Puma.—To show what may be done in the way of training the puma, or Rocky Mountain lion, usually deemed one of the most intractable of animals, William Lant Carpenter writes to "Nature" an account of one he has recently seen at Livingston, Montana. She is now three years old, and was raised from a cub by Mr. W. F. Wittich, who devoted eighteen months to training her. He now has her under complete control. "The beast not having been fed for twenty-four hours, he trailed pieces of raw meat over her nose and mouth, which the puma never attempted to eat until the word was given, as to a dog. Occasional attempts were made, but a twist of the ear by Mr. Wittich was sufficient to control her. When meat was placed a few yards off, the puma fetched it by word of command, and permitted the meat to be taken from her mouth by Mr. Wittich, who fondled her as he would a cat. A very fine dog, a cross between a pure setter and a pure St. Bernard, five years old, named 'Bruce,' is on intimate and even affectionate terms with the puma, who allowed him to remove meat placed upon her jaws, and to eat it. On one occasion the puma (who is often allowed to range the house), the dog, and Mr. Wittich slept together in the same bed. ... In training her he has chiefly used the whip, which she feels only on the nose, ear, and under the tail; he assures me he has made his own teeth meet through her skin in several other parts of her body without her showing any signs of sensation. Her memory is short, and three weeks' intermission of the performance necessitates much extra training and trouble."

Beet-Sugar in Germany.—Baron Lucius's report on the crisis in the beet-sugar industry of Germany, from 1884 to 1887, brings out the curious fact that the largest number of roots were used in the manufacture of sugar during 1884-'85, when the crisis was most intense. This is accounted for by the fact that preparations for extending the manufacture and the cultivation of the roots had been made before prices declined. The increase was also promoted by the general adoption of the processes of diffusion, and the production of a beet-root richer in saccharine matter. The production of molasses was also considerably increased. The Germans are estimated to consume eight kilogrammes of sugar per head; and the exports have increased in greater proportion than the production.